Closed captioning refers to any system that receives, formats, and displays text on a television or other display to thereby allow viewers to access additional or interpretive information about programming content. Closed captions often provide textual transcriptions of the audio portions of programs as the programs progress, thereby allowing the hearing impaired and others to follow the program content without listening to the audio track typically associated with the programming. Motion pictures, video disk (e.g., DVD) content, streamed audio/video, video games and the like may similarly incorporate closed captions using any number of standard or non-standard techniques.
Federal law mandates that all broadcast television programming in the United States must include closed caption information. For conventional digital (e.g., ATSC) television broadcasts, caption streams are typically encoded in a well-known format such as EIA-608 format, EIA-708 format, and/or the like. Other closed captioning formats or standards may be implemented in the United States or elsewhere.
As more and more consumers receive their television programming from broadband sources, the Society of Motion Picture and Television Engineers (SMPTE) and others have recommended a transition from the older standards (e.g., EIA 608/708) to more advanced “timed text” formats such as SMPTE-TT. This newer timed text format incorporates syntax, structures and tags similar to the extensible markup language (XML) to provide more advanced features and to improve flexibility in comparison to the more traditional legacy formats. The SMPTE-TT format is described in SMPTE Standard ST 2052-1-2010, which was approved on Dec. 3, 2010 and is incorporated herein by reference.
Transitioning from legacy formats to timed text formats can create a number of issues in practice. First, incorporating legacy data (e.g., EIA 608/708 data) into timed text formats can be a challenge. Although the SMPTE-TT standard indicates a desire to support legacy formats, it does not presently provide guidance as to how this is to be accomplished. Moreover, challenges can arise in providing timed text within live broadcasts for reasons described more fully below.
It is therefore desirable to provide systems, devices and/or processes that ease the transition from legacy formatting to the newer timed text formats, and that support timed text within live television broadcasts. These and other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background section.